CSEC Industrial Technology Paper 2 May/June 2026 - Free CXC Past Paper with Answers

Define the term 'tolerance' in relation to mechanical design.

State TWO factors that designers should consider when selecting engineering materials for a project.

Sketch the following mechanical keys.

Square

Woodruff

Figure 2 shows the front and side views of an upper link for a mechanical mechanism.

Figure 2. Front and side views of an upper link

Sketch a design for a lower link of the mechanism which meets the following criteria.

• Snugly fits into the $20 \text{ mm} \times 40 \text{ mm}$ slot of the upper link
• Facilitates attachment using the $12 \text{ mm}$ hole

Sketch the MOST suitable fastening device that would firmly connect the upper and lower links.

Identify TWO milling cutters that would be used to cut the $20 \text{ mm} \times 40 \text{ mm}$ slot shown in Figure 2 on page 10.

Materials are subjected to various stresses and strains. Using labelled sketches, show the difference between tensile and compressive stresses.

Complete the table below by stating the function of EACH of the parts labelled A–C in Figure 3.

State ONE action that should be taken to ensure that a vernier caliper maintains its accuracy.

Sketch and label a lathe cutting tool showing the following angles.

• Top rake
• Front clearance

Using a labelled diagram, illustrate a lathe setup for facing.

Figure 4 shows a mild steel shaft measuring $25 \text{ mm}$ in diameter, mounted in a lathe's chuck.

Figure 4. Mild steel shaft

Outline, in sequence, the steps required for cutting the $3 \text{ mm} \times 45^\circ$ chamfer on the revolving workpiece shown in Figure 4.

State TWO finishing techniques that can be applied to protect metal surfaces.

Outline the sequential steps required in order to apply ONE of the finishes identified in (e) (i).

Identify ONE piece of personal protective equipment (PPE) that should be worn when welding, to protect EACH of the following body parts.

Eyes

Lungs

Name TWO gases that are used in welding.

Draw and label a diagram showing the rightward (backhand) gas welding process. The diagram should include the following.

• Position of the rod
• Position of the nozzle/tip
• Welding direction

Sketch a welding corner joint and label the root and the first filler weld passes.

State TWO functions of the coating on an arc welding electrode.

Figure 5 shows a square metal frame measuring $900 \text{ mm} \times 900 \text{ mm}$. The frame is to be fabricated from a length of hollow section mild steel, measuring $25 \text{ mm} \times 25 \text{ mm} \times 6000 \text{ mm}$.

Figure 5. Square metal frame

Using arc welding, outline the sequential steps required in order to fabricate the frame shown in Figure 5.

Sketch the development (layout) of Figure 6, showing the dimensions for the safe edge and seam.

Figure 7 shows a dustpan and handle.

Figure 7. Dustpan and handle

Outline, in sequential order, the operations required in order to attach the handle to the dustpan using $4 \text{ mm}$ diameter pop rivets.

Define the term 'malleability' in relation to the mechanical properties of metal.

For EACH of the following mechanical properties, state ONE example of a metal that fits each description.

Ductility

Brittleness

Gear teeth are typically case-hardened. Outline, in sequential order, the process required in order to case-harden the teeth of a gear.

State TWO safety precautions that should be observed when sand casting.